Pulverizer



Aug. 7, 1935. P. c. FORRESTER 2,012,602

PULVERIZER Filed April 14, 1955 2 Sheets-Sheet l INVENTOR 2% (Z J x/esier B 4 i I I I 4 ATTORNEY Aug. 27, 1935. c, FORRESTEIR 2,012,602

PULVERIZER Filed April 1 4, 1955 2 Sheets-Sheet 2 ATTORNEY Patented Aug. 27, 1935 PATENT OFFICE p 2,012,602. A PuLvEnIzEn Peter'G. Forrester, Tacoma, lash assignor to Forrester-Largilliere Engineering & Milling Company Application April 14, 1933, Serial No. coarse Claims. (01. 33-9) My invention relates, to a pulverizer. More particularly, my invention relates to a pulverizing device for comminuting materials and has V particular reference to providing vibrating means 5- for the screens mounted on the pulverizer for;

screening the material after pulverization.

For purposes of clearness and illustration, I will describe my invention asapplied to the pulverizi'ng of mineral ores; but it is to be distinctly "understood the same is not limited to any such.

specific application. It has also been found successiully applicable to pulverizing diatomaceous earth, cement rock, coal, coke, talc and 1 chips for the manufacture of wood pulp. The present invention is an improvement upon the patent for the pulverizer granted to me'in United States Letters Patent 1,142,159, 'beari'ng date of June 8, 1915;

{Ingeneral, my device of said patent is dis 'tinguis'yl iedfrom the usualball or rod'machine inthat the rods are mounted 'in rings"supported by spiders'so that the machine is a balanced machine and requires much'less'po'werthan' is commonlyem'ployed in the ordinary ball 0:- rod crushingniachine wherein the ballor rods are located only in the bottom of the machine.

Therings in my former machine were rigidlymounted on the shaft on which the drum was;

mounted. In that machinethe screen element's "through which the pulverized material passes,"

in being discharged from the machine, tend to clogl A primary object of my present invention is re erence means for causingsaid screens to vii brat and also to cause therod rings to" vibrate;

whereby the screens aremaintained cle'anjand therefore, in a condition to be highly ei ticient. Also by imparting vibration to the screensI provide. for a'much longer life for said screens. Furas arolling, crushing action with respect to the,

Figure lis a view in perspective of themachine' embodying my invention, with parts broken away; I r I Fig. 2 is a view in cross section of the machine embodying my invention;

Fig. 3 is an enlarged view of the rod and screen mounting;

:Fig, 4 is a view in perspective of the preferred form of screenrholder; I

Fig. .5 is a View inperspective of the screen frame? l Fig. 6 is aview 'in' perspective ofthe central hollow feeddrum shaft element 01' my invention;

' Fig. 7 is a view i-n erossrsecti'onof a-modified form of the screen means formed by combining a fine screen and a coarse screen;

Fig. 8 is a fragmentary view in perspective of said modified form of screen means;

Fig. 9 is a fragmentary'cross'sectional view of a modified form of myinvention showing the screen mounted directly upon the longitudinal beam onwhich beams are mounted the rod rings; -Fig'. 10'is a fragmentary cross sectional view of still a further 'modified form of a pulverizer embodying my -invention-f p v Fig. 11- is a separateview of the drurn opening closing means which may have varying size openings to accommodate material of different character as may be desired and thereby the distribution'of the material regulated with respect to the' leng'th of the 5mm, 7

"A revolvable drum maybe formed with end members IZ mOunted on an axially disposed feed 7 cylinder [3 with. outlet openings M through which the material to be, ground may be passed radially, and members H are joined by crossmembers H which arepreferably in theform of flex-. ible or resilient beams-wooden beams serving admirably for this purpose. A shell l6 also joins the end me nbers lz, said shell havingopenings I1 over, which screens 18 are mounted. Rods l9 are mounted in bundles in rings. 20, and the by lugs il. Screens 18 are mounted in a rectangular. supporting screenframe 22 (see Fig. 3), having lateral members 23 with shelf 24 and medial members 25 with 'shel'ves126. These shelves also extend across the endfmembers of the frame. The ,screen supporting frames 22 are secured to shell", [5' by bolts 21 passing through lateral membars 23. .fIfhe screens I8 are releasably held rings 20 are mounted on the cross members 15 a against shelves 24 and 26 by frames 28, which in I the vibrations possible.

through cross member I5 and medial member 25 with a spacer sleeve 34 between cross member I5 and medial member 25.

Material elevating blades or flanges 35 are mounted on cross'member I5 by bolts 33. These elevating flanges are preferably in spaced rela tion to the feed cylinders I3 so as to permit the material to pass from one to another of the chambers occupied by the bundles of rods I9. I

In the modified form of screen shown in Figs. 7 and 8, a coarse screen 36 is mounted on inclined members 31, leaving opening 38 so that material which is fine enough to pass the coarse screen'36, but toocoarse to pass fine screen I8, may fall back upon the bundles of rods I9 for further grinding. t

In the modified form shown in Fig. 9 the screen supporting frames 39 are mounted directly upon cross members 40, which in this instance are located adjacent the shell I6.

In the modified form shown in Fig. 10 the cross members 4| are located adjacent the shell I6 and betweenadjacent screen supporting frames'42. Rings 43 are separately secured to said cross beams bymeans of bolts 44.

In Fig. 11, feed drum openings II are provided with reduction plates 45 which have smaller openings 46 than openings I4 in the feed drum,

thereby material being fed into the drum may be distributed. That is, with these plates disposed over those openings I4 located in the end portion of the feed drum nearest the material feed spout II, the material will be caused to be distributed more uniformly throughoutthe length of the The mode ofoperation of my invention is as follows:

The material-is fed into the, said cylinder I3,

from which it escapesthrough openings I4 into 40 the chambers in which are mounted the bundles of rods I9. The oversized materialis retained by the rods I9 and gradually groundwhile the finer material sifts through the-rods I 9 and is further pulverized. Subsequently, the coarser material is-reduced in size and is pulverizedby the action of the rods. Any portion of the-oversized partsof the material that escapesto thescreen I8 is picked up bythe elevator blades or flanges 35 and droppedupon, or returnedto the various bundles of rods. It will be noted that a given portion of the material-is not'confined to the action of any. particular bundle or set of rollsor. rods I9, but that the, material is exposed toany V a and all of the various sets of rollers. I

It will be understood, depending of course upon the size of the mill, that there is ordinarily onehalf ton of rods in each ring -each rod weighing from twenty-five to forty. pounds. This is true for .a mill forty-eight .inches in length. Of course, said weight, is greater in a longer mill.

The rolling and tumbling of this weight of rods in the rings 20 set up vibrations, and these "vibrations are taken advantage of by mounting the rod rings on the, crossmembers I5, said mem-- bers being preferably of wood'for treating ores so as to avoid crystallization and to provide resiliency. These cross members I5 are preferably mounted in the peripheral portion of the.

drum so as to -dependand take advantage ofv all The screen supporting members are preferably formed of wooden members in order to provide resiliency as the central mounting means of the screens I8. The, screen supporting members are connected by a bolt and spacer sleeve 34 to the cross member I5. In this wise the vibrations imparted to the cross members by the rods in the rings are transmitted directly to the screens I8 and maintain the same in constant vibration. By having the screens I8 continually in vibration they are maintained clean and in a more highly efiicient condition for performing their function of screening the material. By maintaining the said screens.I8 in a clean condition, also the life of the screen is greatly extended. Screens I8 may be readily replaced, whenever they do become worn, by merely disconnecting screen holder 29 and removing screen frame 28, which serves to clamp the lateral edge portions of screen- .IB. against the shelves 24 and 26. a a

In addition to the fine screen I8 a scalplng or coarse screen 36 may be positioned inwardly of the fine screen I8. By having this screen 36 secured in closed position along the forward or advancing edge when the direction of the rotation of the drum is considered and by having this coarse screen mounted .on wedge or inclined members 31 with respect to the fine screen I4, an opening 38 is provided with respect to the following edge of the coarse screen 36. Thus, if material is of such degree of fineness that it may pass through'the coarse screen 36, but is too coarse to pass through the fine screen I8, it will pass through the opening 31 and fall back upon the 'rods I9 for further pulverizing.

'In this way I eliminate the common trouble where a coarse screen is employed in conjunction with a fine screen to give support to a fine screen and protect the same from having some portion of the material pass through the coarse screen and becoming lodged against the fine screen I8.

This material becomes packed in between the two screens and results in' a clogging of both screens. By positioning the coarse screen 36 in spaced relation, and by having the opening 38,

as herein set forth, provision is made for the ma terial that passes the coarse screen to be returned to be kept in constant agitation and thereby kept clean. Thus, I utilize the inherent vibration of the machine without any separate vibrating mechanism to make the screens I8 most efiicient.

Also, I employ the said vibration to make the rods themselves more eflicient in'their operationby imparting a hammer-like action to said rods in addition to their rolling action, while performing their pulverizing function.

Obviously, changes may be made in the forms, dimensions, and arrangement of the parts of my invention, without departing from the principle thereof, the above settingforth only preferred formsof embodiment.

I claim:

1. A pulverizer embodying a central feed drum shaft having material discharge openings therein; end plates fixedly mounted on said drum shaft; flexible cross members extending-parallel between the said end plates, said members being in spaced relation to said drum shaft; rod rings supported by and mounted between said cross members; movable rods insaid rings causing vibrations; screen supporting frames peripherally mounted for vibratory movement on said end plates; and. means connecting said screen supportingframes to said cross members, whereby the vibrations of said rings are transmitted to said screen supporting frame.v

2. A pulverizer embodying a central hollow feed drum shaft having openings in its peripheral portions for material discharge outlets; plates fixedly mounted on said drum shaft; flexible vibratile means mounted in the peripheral portion of said end plates; vibrating rod rings mounted on said vibratile means; and screen means mounted on said vibratile means, whereby the vibration of said vibrating rod rings are transmitted to said screen means.

3. A pulverizer embodying a central feed drum shaft having material discharge openings therein; end plates fixedly mounted on said drum shaft; flexible wooden cross members extending parallel between the said end plates, said members being in spaced relation to said drum shaft; rod rings supported by and mounted between said cross members; movablerrods in said rings causing vibrations; screen supporting frames peripherally mounted for vibratory movement on said end plates; and means connecting said screen supporting frames to said cross members, whereby the vibrations of said rings are transmitted to said screen supporting frame.

4. A pulverizer embodying a drum; screens mounted for vibratory movement in said drum; vibratile cross members in said drum; grinding means in said drum supported by said vibratile cross members and causing vibrations; and means connecting said screens to said vibratile cross members, whereby the vibrations set ,up in vibratile cross members are communicated to said screens.

5. A pulverizer embodying screens mounted for vibratory movement in said drum; vibratile cross members in said drum; rod rings in said drum supported by said vibratile cross members; grinding rods supported by said rod rings and vibrating said rod rings and said vibratile cross members;

and means connecting said screens and said vi-f bratile cross members, whereby the vibrations set up in said vibratile cross members ar'eflcom- 

